FIELD: electricity.
SUBSTANCE: invention discloses systems, devices and methods of maintaining the charge state of an energy storage device, such as accumulator batteries, flywheels, capacitors and other technologies that are energy-related to electricity, to provide ancillary services. In order to reliably respond to network control requests, charge in an energy storage device is maintained or restored to a given range in a certain manner that optimises readiness of the device to store energy to provide ancillary services in light of the network status. The charge state (SOC) of the energy storage device and network frequency can be controlled. When a request from an operator to control network frequency is not serviced, the charge of the energy storage device can be increased or decreased so that the charge can be maintained within a certain range. Once the SOC falls outside a first range, charge can be added or removed from the energy storage device, when network frequency assumes appropriate values, for example, if network frequency is higher than a first given point or lower than a second given point, respectively.
EFFECT: high reliability.
24 cl, 7 dwg
